Method for determining and monitoring ageing of blood bags

ABSTRACT

The invention concerns a method which consists in determining ageing an ageing index of a blood bag ( 11, 62 ), to determine whether the blood bag is or not suitable for transfusion to a patient. The ageing index is calculated by connecting a silicon chip provided with a loop antenna integral with the blood bag ( 11, 62 ) with an electronic communication device ( 2, 8, 17, 12, 20, 24 ), itself equipped with a loop antenna, connected to a computer ( 9, 13 ) containing appropriate computing software elements. Said ageing index is regularly calculated at the blood transfusion center ( 16 ) from the sample ( 1 ), until it is removed from storage ( 7 ) to be sent to the health-care institution ( 18 ) and to the operating theatre ( 19 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National Stage Application of InternationalApplication No. PCT/FR02/01968, filed Jun. 10, 2002. Further, thepresent application claims priority under 35 U.S.C. §119 of FrenchPatent Application No. 01/07618 filed on Jun. 12, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a method for determining and monitoring theageing of blood bags in blood transfusion centers and health-careinstitutions.

2. Discussion of Background Information

At the present time, blood bags are collected in blood transfusioncenters; each bag is dated at the time the blood is collected, whichindicates the beginning of the life-span of the bag and the by-products,life-span that lasts a predetermined length of time; blood collected inbags is subjected to filtering, centrifugation and separation, whichleads notably to production of a by-product which is a bag of red cellsintended for transfusion whose life-span is forty five days beginning atthe date on which the blood was collected; the bags of red bloodcorpuscles are stored in blood transfusion centers and deliveredaccording to the requirements of health-care institutions. It sometimesoccurs that bags of red blood corpuscles, which had been prepared asprecautionary measures for an operation are not used; as it isimpossible at present to have a firm guarantee of the quality of thecontents of the bag of red blood corpuscles, with a view of them beingre-used, the bag is destroyed. As destruction of unused bags of redblood corpuscles represents at present a loss of twelve percent of theblood bags collected, it is essential to reduce this wastefulness.

As the bags of red blood corpuscles are at present transported betweenthe blood transfusion centre and the health-care institution without anyspecial precautions, a study is under way with a transport company forguaranteeing the continuity of the cold chain between these twoestablishments; in this case, the blood bag is placed in a refrigeratedcontainer inside which a device is placed indicating the temperature inthe container throughout transport; as the bags of red blood corpusclesare placed in an appropriate refrigerator on arrival at the health-careinstitution, these bags can be returned to the blood transfusion centreif they have not been removed from the refrigerator in the mean time, tobe placed at the disposal of a surgeon.

When the blood is collected, it is transferred into a main blood bagconnected to a filter, itself connected to a primary blood bag; theprimary blood bag is part of a group of bags that also include threesecondary bags to which it is connected by flexible tubing arranged inparallel; the blood from the main blood bag is filtered and introducedinto the primary blood bag; the primary blood bag is centrifuged inorder to separate the red cells, platelets and serum which are thenrespectively transferred into each of the three bags and the bagcontaining the red cells is the one used to carry out bloodtransfusions. As a reminder, platelets are isolated only when there is aspecific supply requirement—otherwise they remain with the red cells andonly two secondary bags are used.

A traceability device for blood bags, as per patent applicationFR-9804802 is under development; it integrates a silicon chip with theblood bag; each silicon chip is fitted with a loop antenna whichcommunicates with the loop antenna on an electronic communicationdevice, connected to a computer, capable of supplying the silicon chipon the one hand with energy and on the other with data which it storesin memory and which it is capable of restoring to the said computerthrough the electronic communication device; a mother silicon chip isattached to the mother blood bag which receives all the data concerningthe donor and the results of analyses that have enabled the mother bloodbag to be qualified; the electronic mother chip is fixed on arectangular-shaped flexible chip support several centimeters long, onwhich a metallized loop circuit is printed that forms the communicationsloop antenna; in a preferred version of the invention, the flexible chipsupport for the primary silicon chip is placed on one of the largestsurfaces of the mother blood bag beneath a rectangular label coveringthe major part of one of the principal surfaces; preferably the motherchip support is always put in the same place in relation to the labelfor facilitating positioning of the antenna on the electroniccommunication device. A patent application FR-9908887 describes aweighing and stirring device fitted with an electronic communicationdevice which enables the blood donor's particulars and blood collectionconditions to be recorded in the electronic mother chip on the motherblood bag; the blood in the mother blood bag is transferred through afiltration unit into the primary blood bag; the primary blood bagcomprises a primary silicon chip to which the data contained in theelectronic mother chip is transferred together with information onfiltration conditions; the primary blood bag is then centrifuged; theconstituents are separated and are introduced into the secondary bloodbags; secondary blood bags are equipped with secondary silicon chips,identical to the mother and primary silicon chips, which are fixed to aflexible chip support placed under a label covering one side of thesecondary blood bag, preferably in such a position that, when themother, primary and secondary blood bags are placed above each other,the mother and primary silicon chip supports do not cover each other orthe secondary flexible chip supports; information is entered into thesecondary silicon chips on the secondary bags, in other words the redcell bag, the serum bag and possibly the platelet bag, by transferringdata from the primary silicon chip on the primary blood bag, andcompleting it with data concerning the parameters used for separatingthe blood constituents. Concerning any red cell bag that has been usedfor a blood transfusion, at the end of the bag's use, the secondarysilicon chip integrated into it contains information concerning itsconditions of use and notably the identity of the patient who hasreceived the transfusion.

SUMMARY OF THE INVENTION

The method, according to the invention, provides for formalizing,throughout its existence, the status of a mother, primary or secondaryblood bag, referred to hereafter as “blood bag”, equipped with a siliconchip, in relation to the phenomenon of biodegradation which is qualifiedhereafter as “ageing”, so that, at any given time and in the mostaccurate manner possible, it may be known whether the blood bag isqualified for use in a transfusion.

The invention also provides for a method of qualifying, re-qualifyingand disqualifying a blood bag that includes a permanently attached asilicon chip fitted with a loop antenna capable of communicating with anelectronic communication device, wherein the method comprisesestablishing an ageing index of the blood bag when blood is collectedfrom a donor in a blood transfusion center, entering on the siliconchip, using the electronic communication device, a value of the ageingindex as the ageing index evolves progressively towards a maximum value,which, when reached, leads to the blood bag being disqualified,calculating the value of the ageing index between two successive momentsin time of a period of time by taking into account the following:bacteriological analyses; the value of the ageing index at the beginningof the period; a duration of the period; and environmentalcharacteristics of the blood bag during the period under consideration.The ageing index is calculated when the blood bag enters or leaves acontrolled atmosphere chamber and when a patient is transfused with theblood contained in the blood bag. A new ageing index value is entered inthe silicon chip after each calculation.

The ageing index can be calculated using pre-determined ageing modelscharacteristic of the period under consideration and established byexperiment on a basis of empirical formulae. The ageing index can becalculated when the patient is transfused in a health-care institution.The establishing may comprise establishing the ageing index of the bloodbag at an initial moment when blood is collected from a donor in a bloodtransfusion center. The method may further comprise determining andmonitoring an evolution of an ageing index of the blood bag so that adetermination can be made as to whether or not the blood bag can be usedto transfuse a patient. The electronic communication device may beequipped with a loop antenna connected to one of a computer and acalculating device. The electronic communication device is coupled to aweighing and stirring device. The ageing index may evolve progressivelytowards the maximum value depending on the time elapsed andenvironmental conditions. The ageing index may be calculated when theblood bag enters or leaves a controlled atmosphere chamber at the bloodtransfusion center and further comprising, when needed, recalculatingthe ageing index when stocks of blood bags are controlled forstatistical reasons and when the blood bag is removed to be dispatchedto a health-care institution. The electronic communication device may beconnected to a computer and wherein the recalculating utilizes anotherelectronic communication device connected to the computer. Thecalculating may comprise calculating automatically at close and regularintervals of time, whereby the blood bag may be removed at any momentafter an up-to-date ageing index has been entered on the silicon chipand dispatched to an operating theater. The electronic communicationdevice may be connected to a computer and wherein the establishingoccurs before a patient is transfused with the blood contained in theblood bag using another electronic communication device connected toanother second computer. The method may further comprise one of: placingan unused blood bag back into the controlled atmosphere chamber; andreturning an unused blood bag to the blood transfusion center. Themethod may further comprise checking, at the moment of transfusion, aqualification of the blood bag using another independent electroniccommunication device. The other independent electronic communicationdevice may be connected to a calculating system that is capable ofcomparing a length of time spent by the blood bag outside the controlledatmosphere chamber with an allocated length of time which corresponds toa life-span remaining in a non-controlled atmosphere outside thecontrolled atmosphere chamber. The method may further comprise, when theblood bag is determined to no longer be usable for transfusions,re-qualifying the blood bag using the electronic communication deviceconnected to a computer. The controlled atmosphere chamber may be acellular controlled atmosphere chamber and further comprising using acomputer to manage a stock of blood bags inside the cellular controlledatmosphere chamber, whereby each compartment of the cellular controlledatmosphere chamber is allocated an address. The computer may bestructured and arranged such that a user requiring the blood bags canenter requirements on the computer and provide a user identity, and thecomputer indicates in reply addresses of the compartments correspondingto the entered requirements. The blood bag may be located in one of anumber of compartments of the controlled atmosphere chamber and themethod may further comprise determining when the value of the ageingindex the blood bag arranged in the controlled atmosphere chamber hasexceeded the maximum value and indicating with a computer an address ofthe compartment containing the blood bag so that the blood bagidentified for destruction.

The invention also provides for an arrangement for implementing themethod described above, wherein the arrangement comprises: a cellularcontrolled atmosphere chamber having compartments for storing bloodbags, one of the compartments comprising a horizontal lower surfacecapable of holding a blood bag, a loop antenna integrated in thehorizontal lower surface in such a way that the loop antenna of thesilicon chip can be located opposite the loop antenna of thecompartment, and a dedicated electronic communication device integratedinto the horizontal lower surface. The dedicated electroniccommunication device is connected to a computer.

Each compartment may comprise a lower horizontal surface having anintegrated loop antenna and a dedicated electronic communication deviceconnected to the computer, whereby the computer stores characteristicsof the blood bags contained in the compartments and checks everycompartment at regular intervals in time to determine whether a bloodbag is in fact present in each compartment and calculates an ageingindex so that the ageing index can be incorporated in the silicon chipof each blood bag with a time and a date of the calculation. Thecompartments may be arranged within a storage unit capable of being putinside the controlled atmosphere chamber. The compartments may compriseindependent drawers having a back, side faces with guide rails arrangedon outside surfaces, and the independent drawers may run on horizontalslide-ways attached to rack arrangements. The independent drawers may bearranged within a storage unit capable of being put inside thecontrolled atmosphere chamber. The compartments may include indicatorlamps, whereby the indicator lamps act to identify compartmentscontaining a disqualified blood from compartments that do not contain ablood bag or from compartments whose dedicated electronic communicationdevice is not operational.

The invention also provides for a method of qualifying, re-qualifyingand disqualifying a blood bag that includes a silicon chip and a loopantenna capable of communicating with an electronic communicationdevice, wherein the method comprises entering on the silicon chip, usingthe electronic communication device, a value of the ageing index as theageing index evolves progressively from when blood is collected from adonor in a blood transfusion center towards a maximum value, which, whenreached, leads to the blood bag being disqualified, calculating, atdifferent points in a period of time, the value of the ageing index bytaking into account the following: bacteriological analyses; the valueof the ageing index at the beginning of the period; a duration of theperiod; and environmental characteristics of the blood bag during theperiod under consideration. The calculating occurs when the blood bagenters or leaves a controlled atmosphere chamber and when a patient istransfused with the blood contained in the blood bag.

A new ageing index value can be entered in the silicon chip after eachcalculation.

The invention also provides for a method of qualifying, re-qualifyingand disqualifying a blood bag that includes a silicon chip and anantenna capable of communicating with an electronic communicationdevice, wherein the method comprises entering on the silicon chip, usingthe electronic communication device, a value of the ageing index as theageing index evolves progressively from when blood is collected from adonor towards a maximum value, which, when reached, leads to the bloodbag being disqualified, calculating, at different points in a period oftime, the value of the ageing index by taking into account thefollowing: bacteriological analyses; the value of the ageing index atthe beginning of the period; a duration of the period; and environmentalcharacteristics of the blood bag during the period under consideration.The calculating occurs when the blood bag enters or leaves a controlledatmosphere chamber and when a patient is transfused with the bloodcontained in the blood bag.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents a schematic diagram of the various phases throughwhich a blood bag may pass using the method of the invention.

FIG. 2 represents a partial blown-up view of a storage device for bloodbags fitted with an automatic device for monitoring blood bag ageing.

FIGS. 3A and 3B represent another method of making the storage device asper FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

The method provides for determining an ageing index for the blood bag,which defines the blood bag's qualification or unsuitability for beingused or not used for transfusion to a patient; the blood bag is thenhereafter said to be “qualified” or “unsuitable”. The ageing index iscalculated by putting the silicon chip on the blood bag in relation withan electronic communication device itself connected to a computercontaining appropriate computing software elements. This index evolvesprogressively, depending notably on the blood bag's age andenvironmental conditions, towards a maximum value which, when it isreached, leads to the blood bag being declared unsuitable and beingdestroyed. Variation in this ageing index is calculated between twosuccessive moments in time constituting a period, using a model referredto hereafter as “predetermined ageing model” that characterizes theperiod under consideration and which is established by experiment, basedon empirical formulae taking into account the results of bacterialanalyses, the blood bag's environment during the period underconsideration and parameters such as the time and/or the temperature andvalue of the ageing index at the beginning of the period. This ageingindex is initiated when the blood is collected, the date of which isrecorded in the silicon chip on the primary blood bag; this supposesthat a weighing and stirring device 1 (FIG. 1) supporting the blood bagis fitted with a first electronic communication device 2 which enablesthe date and time of blood collection to be recorded on the silicon chipon the primary blood bag, as well as data and particulars concerning thedonor and blood collection conditions. The ageing index is calculatedeach time the blood bag changes its environment, for example at entry 3and 5 and exit 4 and 6 of a storage zone, where atmospheric parametersare monitored, referred to hereafter as “controlled atmosphere chamber”7 at which occasion the new ageing index value is recorded on thesilicon chip on the blood bag and the blood bag is referred to as“re-qualified” if the ageing index is lower than its maximum value:otherwise it is unsuitable. Such an operation can be carried outmanually when the blood bag is extracted from a controlled atmospherechamber 7 by using a second electronic communication device 8 connectedto an initial computer 9 containing the appropriate software elements.Such an operation can also be carried out automatically in a controlledatmosphere chamber where the silicon chip of each blood bag ills placedin permanent relation with a dedicated electronic communication device12 connected to a second computer 13 containing the appropriate softwareelements. This type of controlled atmosphere chamber is referred tohereafter as “cellular controlled atmosphere chamber” 10. In theseconditions the blood bag 11 can be taken out at any time after itsageing index has been updated on its silicon chip.

For example: when blood is collected, the initial time is recorded bythe weighing and stirring device 1 on the primary silicon chip on theprimary blood bag, which is then processed in a centrifugal separator14. During the separation phase 15, the red cells are fed into one ofthe three secondary bags to constitute the blood bag; the data containedin the primary silicon chip is transferred to the silicon chip on theblood bag at the same time as data concerning centrifugation andseparation. The blood bag is then directed to the controlled atmospherechamber 7 of the blood transfusion center 16 and an initial ageing indexvalue is calculated by placing its silicon chip in communication with aninitial computer 9 via a third electronic communication device 17.During storage in the controlled atmosphere chamber 7, the blood bag 62is not in principle monitored from an ageing point of view other thanfor statistical controls on the state of stocks, at which time theageing index is updated for the blood bag that has been controlled 62.When the blood bag 62 is removed for a transport operation 25 to ahealth-care institution 18, the ageing index is updated, compared to thedate of the last ageing index update using the second electroniccommunication device 8. Ageing indexes are then updated in thehealth-care institution 18 successively on entry in the cellularcontrolled atmosphere chamber 10 and later at close and regularintervals until blood bag 11 is removed to be directed to an operatingtheatre 19 where it is rechecked for the last time before transfusion byway of a fourth electronic communication device 20. If the blood bag isnot used, it is returned to the cellular controlled atmosphere chamber11 and even back to the blood transfusion centre 16 following the sameprocedure as the procedure described above.

When the blood bag 11 is in a cellular controlled atmosphere chamber 10of a health-care institution 18, the silicon chip associated with eachblood bag 11 is connected permanently to the second computer 13belonging to the health-care institution 18 through a dedicatedelectronic communication device 12. At regular intervals, the secondcomputer 13 checks the presence of the blood bag 11 in the cellularcontrolled atmosphere chamber 10 and the temperature therein in order tocalculate the ageing of the blood bag 11 compared with tables of valuesestablished by experiment. The ageing calculation can be made, forexample, by determining two parameters—the temperature and the time thathas elapsed since the last update. An average temperature is determinedwhich is weighted depending on its intrinsic value and depending on thetime under consideration related to the initial time, determined on theweighing and stirring device 1 when the blood was collected. Thisweighted average temperature is then integrated in relation to the timeto provide a value that measures the variation in the ageing index. Tocarry out the update operation, the new ageing index value is recordedon the silicon chip together with the date and time it was determined.

A maximum ageing index value is determined by experiment, whichautomatically leads to the unsuitability and destruction 21, 22 of theblood bag when the maximum value is reached.

When the blood bag 11 is removed from a cellular controlled atmospherechamber 10, the silicon chip includes the value of the last ageing indexcalculated and the date and time at which this was done. If this bloodbag 11 is made available in an operating theatre 19, the latter isequipped with the fourth electronic device 20 for communicating with thesilicon chip on the blood bag which can read the value of the ageingindex at the date of the last control. As, in principle, the temperatureis no longer controlled from the moment the blood bag is taken from thecellular controlled atmosphere chamber 10, a mean evolution curve of thetemperature is drawn up by experiment, depending on the time, whichcontributes to establishing pre-determined ageing model enabling theageing index to be updated. If the fourth electronic communicationdevice 20 is connected to the second computer 13 it is the latter whichcalculates the new ageing index which is validated and recorded on thesilicon chip. If a fifth independent electronic communication device 23serving to control the blood bag at the time of the blood transfusion isnot connected to a computer, as may be the case when blood from theblood bag is transfused during transport of a person after an accident,it can be equipped with simplified way of calculation 24 givinginformation as to whether the bag is still qualified without howeverrecalculating the ageing index; in fact a safety margin can be definedfor the ageing index, when the index gets close to its maximum value,defined by the blood bag's remaining life-span in non-controlledatmosphere. If the blood bag 11 has used part of its remaining life-spanduring a period when it was in the controlled atmosphere chamber 10, itis disqualified and sent away for destruction 21. If the fifthindependent electronic communication device 23 detects that the timeallowed after the blood bag has left the cellular controlled atmospherechamber 10 has elapsed, the blood bag is declared doubtful and must bere-qualified by putting it into communication with a dedicatedelectronic communication device 12 or the fourth electroniccommunication device 20 connected to the second computer 13. If theblood bag has not been used and is returned to the cellular controlledatmosphere chamber 10, the continuous ageing measurement method isre-initiated after calculating how much the blood pocket 11 has agedduring its exposure to non-controlled atmosphere, using a pre-determinedageing model such as the one described above and the blood bag is eitherre-qualified or disqualified and sent away for destruction 21. Severalpre-determined aging models can be defined for keeping as close aspossible to the realities of the ageing process depending on theconditions under which the blood bag has been manipulated: manipulationsconcern the blood collection phase, the constituent centrifugation 14and separation 15 phases, the transport-under-controlled-atmospherephase 25 between the transfusion centre 16 and the health careinstitution 18.

In a preferred version of the device for implementing the method, in thehealth-care institution 18, blood bag storage 11 is done in a cellularcontrolled atmosphere chamber 39 made up of a number of virtuallyparallelepiped compartments 26 (FIG. 2). The compartments 26 notablyinclude a very wide and horizontal lower surface 27 surrounded by threesmall side surfaces 28, 29, 30 for holding a blood bag 31 and keeping itin position so that the loop antenna 32 of the silicon chip 33, fixed toa flexible silicon chip support 34 is opposite the loop antenna 36 of adedicated electronic communication device 35 integrated into the widehorizontal surface 27. This supposes that the flexible silicon chipsupport 34 is always in the same position under a label 37, as describedabove and that the latter is always turned towards the wide horizontallower surface 27. The compartments 26 are cut-out with openings 38 toallow cooling air to circulate from one compartment to another; eachdedicated electronic communication device 35 is connected to the samecomputer that memorizes all or part of the characteristics of the bloodbags 31 contained in compartments 26 and examines each compartment 26 atclose and regular intervals in time to check that the blood bag 31 is infact present in the compartment 26 and to calculate its ageing index sothat this index can be integrated into the silicon chip 33 with the dateand time when the calculation was made.

Blood bag stock management in the cellular controlled atmosphere chamber39 is preferably carried out by the computer using an address allocatedto each compartment 26 and a certain number of hierarchical criteria.The person responsible for taking out the blood bags enters thecharacteristics of his or her requirement onto the computer screen and,notably, gives his or her identity and the computer indicates in replythe addresses of the compartments 26 containing the blood bags 31 thatcorrespond to the requirement and to the hierarchical criteria forremoving them. The fact that the blood bags are really removed iscontrolled by detecting that the compartment 26 is empty; removing bloodbags from compartments 26 other than those indicated for removalimmediately sets off an alarm. The end of the removal operation givesrise to the issue of an electronic receipt on behalf of the personresponsible for removing the bags.

Blood bags 43 contained in the cellular controlled atmosphere chamber39, which have reached the maximum ageing index are downgraded andindicated on the computer screen so that they can be removed from theircompartment for destruction.

Concerning blood bags being put into a cellular controlled atmospherechamber 39, they are placed in empty compartments 26. The computerdetects that a compartment that was previously empty is now occupied asit can read the silicon chip 33 placed under the label 37 of the bloodbag 31. It can manage its ageing process on the basis of informationcontained in the silicon chip 33, for example, in the case ofhealth-care institutions it will detect the course of its existence byreading the silicon chip 33. if the blood bag arrives from thetransfusion centre 16 (FIG. 1) it updates the ageing index and puts theblood bag in the waiting list for an operation. If the blood bag comesback from the operating theatre 19, it must be re-qualified andrepositioned depending on hierarchical criteria, either for return tothe blood transfusion centre 16, for disqualification and destruction21, or for return to the waiting list for a new operation.

To facilitate filling compartments 26 (FIG. 2) and removing blood bags31, compartments may be equipped with colored indicator lamps, forexample, a green indicator lamp 40 that lights up when a compartment 26contains a blood bag 31 that has been selected for removal. A redindicator lamp that lights up when the computer detects that acompartment 44 contains a blood bag that is no longer valid 43. Possiblya white indicator lamp for an empty compartment 61 can be utilized. Thelatter white indicator lamp 42 will reveal a dysfunction in thededicated electronic communication device 35 or the silicon chip 33, ifever it lights up on a compartment that contains a blood bag. Bylighting up when a blood bag 31 or 43 is inserted, the green 40 or red42 indicator lamp indicates that the computer has taken the blood bag'scharacteristics into account.

On a practical level, the compartments 26 in a cellular controlledatmosphere chamber 39 may be elements that are part of a larger unit,which is placed inside a non-equipped cellular controlled atmospherechamber. Compartments 26 are preferably made from plastic reinforcedwith a minimum amount of metal elements and are sufficiently far apartvertically for the loop antenna on the dedicated electroniccommunication device 35 fitted in the wide lower horizontal surface 27to only react to the blood bag in the compartment 26 concerned withoutaffecting blood bags contained in other compartments 26. The indicatorlamps 40, 41, 42 are mounted on the wide horizontal lower surface 27near the side opening of the compartment 26.

In a variant version of the device for implementing the method, thecompartments are independent drawers 45 (FIG. 3A) made up of a widelower surface 46 incorporating a dedicated electronic communicationsdevice 47 and the indicator lamps 48 with one side 49 open for insertingthe blood bag. The dedicated electronic communication device 47 isconnected to a primary connection device 50 (FIG. 3B), incorporated intothe small side face that forms the back 51 (FIG. 3A) of the independentdrawer 45. The small side faces 52 and 53, which are parallel to eachother, possess guide rails 54 on their outside surfaces. A storage unit55 designed to hold the independent drawers 45 is composed of verticallyplaced rack arrangements 56 that are parallel to each other at asuitable distance from each other for holding the independent drawers 45and possessing horizontal slide-ways 57 at regular intervals, on whichthe guide rails 54 on the independent drawers can run; the bottom ofunit 58 of the storage unit 55 contains secondary connecting devices 59on which fasten the primary connecting devices 50 on the independentdrawers 45. The male connectors 59 are connected to the computer. Thefront side of the rack arrangement 56 may be fitted with a lockingdevice 60 for holding the independent drawers 45 in place.

1. A method of qualifying, re-qualifying and disqualifying a blood bagthat includes a silicon chip and an antenna capable of communicatingwith plural different electronic communication devices, the methodcomprising: providing a plurality of different electronic communicationdevices; arranging one of the plurality of different electroniccommunication devices on a weighing and stirring device; establishing amaximum value of an ageing index to determine when the blood bag isdisqualified; obtaining a value of the ageing index from the siliconchip at successive moments in time using another of the plurality ofdifferent electronic communication devices; after the establishing ofthe maximum value and the obtaining, entering on the silicon chip thevalue of the ageing index as the ageing index evolves progressively fromwhen blood is collected from a donor towards the maximum value, which,when reached, leads to the blood bag being disqualified; calculating, ina health-care institution and at different points in a period of time,the value of the ageing index using a pre-determined ageing model and bytaking into account the following: bacteriological analyses; the valueof the ageing index at the beginning of the period; a duration of theperiod; and environmental characteristics of the blood bag during theperiod under consideration; re-qualifying the blood bag in thehealth-care institution when the value of the ageing index of the bloodbag is lower than the maximum value and when a new value of the ageingindex is recorded on the silicon chip; and disqualifying the blood bagwhen the ageing index reaches the maximum value, wherein there-qualifying occurs when the blood bag enters or leaves a controlledatmosphere chamber and the calculating occurs at successive timesbetween the time the blood is collected and when a patient is transfusedwith the blood contained in the blood bag, wherein the re-qualifyingtakes place automatically in the controlled atmosphere chamber andoccurs when the blood bag returns to the controlled atmosphere chamber,wherein, when the blood bag is removed from the controlled atmospherechamber, the chip contains the value of the last ageing index calculatedas well as the date and time that this was done, and wherein thepre-determined ageing model takes account of the following conditionsunder which the blood bag is manipulated: blood collection; constituentcentrifugation and separation; and transport under controlled atmospherebetween a transfusion center and the health care institution.
 2. Amethod of qualifying, re-qualifying and disqualifying a blood bag thatincludes a permanently attached a silicon chip fitted with a loopantenna capable of communicating with electronic communication devices,the method comprising: providing an electronic communication device;arranging the electronic communication device on a weighing and stirringdevice; establishing an ageing index of the blood bag when blood iscollected from a donor in a blood transfusion center; establishing amaximum value of the ageing index to determine when the blood bag isdisqualified; after the establishing of the ageing index and the maximumvalue, entering on the silicon chip, using another electroniccommunication device, a value of the ageing index as the ageing indexevolves progressively towards the maximum value, which, when reached,leads to the blood bag being disqualified; calculating the value of theageing index between two successive moments in time of a period of timeby taking into account the following: bacteriological analyses; thevalue of the ageing index at the beginning of the period; a duration ofthe period; and environmental characteristics of the blood bag duringthe period under consideration; re-qualifying the blood bag when thevalue of the ageing index of the blood bag is lower than the maximumvalue and when a new value of the ageing index is recorded on thesilicon chip; and disqualifying the blood bag when the ageing indexreaches the maximum value, wherein the re-qualifying takes placeautomatically in a controlled atmosphere chamber and occurs when theblood bag returns to the controlled atmosphere chamber, wherein theageing index is calculated when the blood bag enters or leaves thecontrolled atmosphere chamber and when a patient is transfused with theblood contained in the blood bag, wherein a new ageing index value isentered in the silicon chip after each calculation, wherein, when theblood bag is removed from the controlled atmosphere chamber, the chipcontains the value of the last ageing index calculated as well as thedate and time that this was done, and wherein the calculating utilizes apre-determined ageing model which takes account of the followingconditions under which the blood bag is manipulated: blood collection;constituent centrifugation and separation; and transport undercontrolled atmosphere between the blood transfusion center and a healthcare institution.
 3. A method of qualifying, re-qualifying anddisqualifying a blood bag that includes a silicon chip and a loopantenna capable of communicating with a plurality of electroniccommunication devices, the method comprising: providing a plurality ofelectronic communication devices; arranging one of the plurality ofelectronic communication devices on a weighing and stirring device;establishing a maximum value of the ageing index to determine when theblood bag is disqualified; obtaining a value of the ageing index fromthe silicon chip at successive moments in time; after the establishingof the maximum value and the obtaining, entering on the silicon chip thevalue of the ageing index as the ageing index evolves progressively fromwhen blood is collected from a donor in a blood transfusion centertowards the maximum value, which, when reached, leads to the blood bagbeing disqualified; calculating, at different points in a period oftime, the value of the ageing index by taking into account thefollowing: bacteriological analyses; the value of the ageing index atthe beginning of the period; a duration of the period; and environmentalcharacteristics of the blood bag during the period under consideration;re-qualifying the blood bag when the value of the ageing index of theblood bag is lower than the maximum value and when a new value of theageing index is recorded on the silicon chip; and disqualifying theblood bag when the ageing index reaches the maximum value, wherein there-qualifying takes place automatically in a controlled atmospherechamber and occurs when the blood bag returns to the controlledatmosphere chamber, wherein the calculating occurs when the blood bagenters or leaves the controlled atmosphere chamber and when a patient istransfused with the blood contained in the blood bag, wherein, when theblood bag is removed from the controlled atmosphere chamber, the chipcontains the value of the last ageing index calculated as well as thedate and time that this was done, wherein the ageing index is updated ina health-care institution successively between the time the blood iscollected and the time when the blood is transfused, wherein thecalculating utilizes a pre-determined ageing model which takes accountof the following conditions under which the blood bag is manipulated:blood collection; constituent centrifugation and separation; andtransport under controlled atmosphere between the blood transfusioncenter and the health care institution.